Dow Jones Insight is applying text analysis to thousands of documents to measure trends, such as favorability and issue coverage of the presidential candidates over time. In the first example below, Dow Jones Insight parsed 26,435 documents, including English language newspapers, magazine, transcripts from broadcasts and news wire services.

Favorable and unfavorable ratings are assigned based on the words in proximity to a candidate's name. Neutral documents are excluded.
Dow Jones Insight
Differences in domestic issue coverage between Obama and Clinton is negligible, while "terrorism" and "health care" show a noticeable difference. Obama has more mentions in close proximity to terrorism to Clinton's edge in health care.
Dow Jones Insight

Dow Jones is pitching the service as a generalized tool for analyzing the impact of media coverage, and targeting corporations, as well as political candidates, who need competitive insight. Other services, such as Nielsen BuzzMetrics and BuzzLogic, provide similar kinds of media analysis based on parsing a variety of document types.